The present invention relates to a polyurethane-urea elastomer wherein the soft segment is made from a copolymer of propylene oxide and tetrahydrofuran. More specifically, the invention relates to the production of solution and bulk chain extended elastomers, one component of which comprises propylene oxide and tetrahydrofuran copolymers which can be utilized in various forming operations such as molding, casting, extruding and the like to manufacture various articles.
Heretofore, polyurethanes have been generally produced from various hydroxyl terminated low molecular weight polymers such as polyesters, polyethers and the like as well as from a number of specific polymers such as either only poly(propylene oxide) or poly(tetrahydrofuran) and blends thereof. In general, these polymers do not possess good flexibility life at ambient temperatures.
More recently, U.S. Pat. No. 3,404,131, granted Oct. 1, 1968 to Taub, relates to polyurethane-urea elastomers wherein a molar insufficiency of an aromatic diisocyanate is utilized followed by an adequate remaining excess molar amount of an aliphatic diisocyanate with the copolymer then extended with solely a single aliphatic diamine, p-menthane-1,8-diamine. However, this polymer does not relate to and cannot be utilized for the production of bulk polyurethane-urea elastomers. Moreover, properties of the produced elastomers are generally poor.
U.S. Pat. No. 3,425,999 granted Feb. 4, 1969 to Axelrood, also relates to polyurethane-urea elastomers utilizing a copolymer of ethylene oxide and tetrahydrofuran having a hydroxyl-containing compound of a functionality of at least two. This patent solely utilizes ethylene oxide as a comonomer with tetrahydrofuran, does not relate to a solution process polymer and the polymer has very poor physical properties.